--- title: "Iterative and incremental model" subject: "ICT Project Management" chapter: 4 key: "semester_7/ict_project_management:iterative-incremental-model" source: https://www.bctengineer.com/q/semester_7/ict_project_management/iterative-incremental-model site: BCT Engineering --- # Iterative and incremental model ICT Project Management · Chapter 4: Project Management - Asked in: year not given - Video: [What is Iterative and Incremental development?](https://www.youtube.com/watch?v=wQyW9uxaz5o) — Software Testing 101 - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/ict_project_management/iterative-incremental-model - Whole chapter: https://www.bctengineer.com/md/semester_7/ict_project_management/chapter-4 ## Question What do you mean by iterative and incremental model? Explain it in detail. ## Short answer The iterative and incremental model builds the system in repeated cycles, delivering small increments. Each iteration refines and adds functionality based on feedback. It allows early working software and easier change accommodation, but requires good planning and may increase cost. ## Answer The **iterative and incremental model** builds the system in repeated cycles (iterations), delivering the product in small parts (increments). Rather than completing everything in one pass as in waterfall, a basic version is built first and then improved and extended in later cycles. - **Iterative**: repeat the development cycle to refine and improve the same parts (rework based on feedback). - **Incremental**: add new functionality in each cycle, so the system grows. ```text Increment 1: Req -> Design -> Code -> Test -> Release 1 Increment 2: Req -> Design -> Code -> Test -> Release 2 Increment 3: Req -> Design -> Code -> Test -> Release 3 (full system) ``` #### Working 1. Collect and outline overall requirements; set priorities. 2. Choose the most important features for the first increment. 3. Design, develop and test that increment. 4. Deploy it to users and obtain feedback. 5. Plan the next increment including changes and new features. 6. Repeat until the complete system is delivered. #### Advantages - Working software is available early, so users give feedback early. - Easier to accommodate changes in requirements. - Risk is reduced as problems appear in earlier iterations. - Testing and debugging are done on small pieces. - Lower initial cost; customer benefit earlier. #### Disadvantages - Needs good planning and design to integrate increments. - Overall architecture issues may appear later. - Total cost may rise because of rework. - More management effort and documentation tracking. #### Example A college ERP is released in increments: first admission, then examination, then library and accounts. The college starts using the admission module within two months. Agile, spiral and RUP are examples of iterative-incremental approaches. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is the difference between iterative and incremental? A. Iterative adds new functions; incremental repeats rework B. Both mean building everything in one pass C. Iterative refines the same parts through rework; incremental adds new functionality each cycle D. Iterative means no testing; incremental means no design Answer: C. Iteration improves existing parts with feedback, while increments make the system grow. (Key point: Iterative vs incremental) 2. How is the first increment chosen? A. The easiest documentation is written first B. The most important features are selected by priority C. All features are built at once D. The least important features are built first Answer: B. Requirements are outlined and prioritised, and the most important features go first. (Key point: First increment) 3. Why is risk reduced in this model? A. Problems appear in earlier iterations on small pieces B. Requirements never change C. No integration is needed D. Only one release is made Answer: A. Small pieces are built, tested and fed back early so issues surface sooner. (Key point: Advantage) 4. Which is a disadvantage of the model? A. Users see software only at the end B. It cannot accommodate changes C. It has no testing D. It needs good planning and design so increments integrate, and rework may raise cost Answer: D. Integration of increments requires good architecture, and rework can add cost. (Key point: Disadvantage) ## Related in ICT Project Management - [Project life cycles in detail](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Aproject-life-cycles) — ICT Project Management, chapter 4 - [Conventional waterfall model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Awaterfall-model) — ICT Project Management, chapter 4 - [Agile model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Aagile-model) — ICT Project Management, chapter 4 - [Lean model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Alean-model) — ICT Project Management, chapter 4 - [Project management maturity model](https://www.bctengineer.com/question.md?key=semester_7%2Fict_project_management%3Apm-maturity-model) — ICT Project Management, chapter 10 ## Related in other subjects - [Iterative process of model calibration](https://www.bctengineer.com/question.md?key=semester_8%2Fsimulation_and_modeling%3Acalibration-iterative-process) — Simulation and Modeling, chapter 7, asked 4× - [Incremental model of a transmission line](https://www.bctengineer.com/question.md?key=semester_8%2Ftelecommunications%3Atransmission-line-incremental-model) — Telecommunications, chapter 2 - [Recursion; iterative vs recursive choice](https://www.bctengineer.com/question.md?key=semester_4%2Fdata_structure_and_algorithm%3Adefine-recursion-iterative-vs-recursive) — Data Structure and Algorithm, chapter 5 - [Steady 2D model: seepage under a dam](https://www.bctengineer.com/question.md?key=semester_8%2Fcomputational_techniques_in_civil_engineering%3Aseepage-under-dam-2d-model) — Computational Techniques in Civil Engineering, chapter 7, asked 3×